Claude Skills by AratKruglik

Angular 18-21 project structure, standalone components vs NgModule, control flow (@if/@for/@switch + *ngIf/*ngFor legacy), decorators, dependency injection (inject() function), lifecycle hooks, pipes, Angular Universal SSR pointer. Use this skill to: - Detect project style (standalone vs NgModule) and apply matching patterns. - Pick correct decorators and DI approach. - Use modern control flow (@if/@for/@switch) in Angular 17+ projects. - Apply `inject()` function over constructor injection ...

Angular forms: Reactive Forms (preferred — typed FormGroup/FormControl since Angular 14, FormBuilder, custom + async validators, FormArray, multi-step) and Template-driven (`[(ngModel)]` + FormsModule). Validation strategies, server error mapping, accessibility. Use this skill to: - Build Reactive Forms with typed FormGroup/FormControl. - Use FormBuilder для concise syntax. - Implement custom synchronous and async validators. - Wire FormArray for dynamic field lists. - Map server errors back...

Angular Router (built-in `@angular/router`) — route configuration for standalone and NgModule projects, functional guards (Angular 14.1+), lazy loading, route resolvers, typed params via signals/observables, programmatic navigation, route data and meta. Use this skill to: - Configure routes (standalone-style or NgModule-style). - Use functional guards (canActivate as function, preferred over class-based in 17+). - Lazy-load components or feature modules. - Implement auth guards via route met...

State management for Angular 18-21: signals (signal/computed/effect), services-as-state, NgRx Store + Effects + Selectors, NgRx Component Store, NgRx Signals (newer signal-based store). RxJS essentials — operators, async pipe, takeUntilDestroyed, signal/observable interop. Use this skill to: - Pick the right state tool (signals / services / NgRx variant / vue-query equivalent). - Use signals correctly (signal/computed/effect — when each). - Build a Pinia-style service-as-state singleton. - S...

Testing Angular 18-21: TestBed, component harnesses (@angular/cdk/testing), Karma+Jasmine (default historical) vs Jest (jest-preset-angular, modern), Angular Testing Library (RTL-style). HttpClient mocking via HttpTestingController. NgRx Effects testing. Cypress / Playwright e2e. Use this skill to: - Detect runner (Karma+Jasmine vs Jest) and configure correctly. - Write component tests with TestBed. - Use component harnesses for Material / custom UI components. - Mock HttpClient via provideH...

ASP.NET Core web framework conventions: Minimal API vs MVC controllers, Program.cs composition, DI lifetimes (Scoped/Singleton/Transient), Options pattern with IOptions<T>, middleware ordering (HTTPS redirect → routing → authentication → authorization), model binding and validation (FluentValidation / DataAnnotations), ProblemDetails error handling, structured logging with ILogger<T>, configuration layering (appsettings.json + environment variables + User Secrets), and health checks. Works al...

Entity Framework Core patterns for ASP.NET Core projects: DbContext design, code-first entity configuration (Fluent API via IEntityTypeConfiguration<T>), relations (HasOne/HasMany, cascade/restrict/set-null), indexes and unique constraints, projection to DTOs (Select + AsNoTracking), avoiding N+1 (Include, AsSplitQuery), transactions, parameterized raw SQL (FromSql with FormattableString), and connection string from IConfiguration. Works alongside aspnet-core-plugin:aspnet-conventions. Use t...

Modern C# idioms for any .NET project (C# 10+, .NET 6+): nullable reference types, records, readonly structs, primary constructors, pattern matching, async/await with CancellationToken, IDisposable/IAsyncDisposable, file-scoped namespaces, var usage, naming conventions (PascalCase members, _camelCase fields, I-prefixed interfaces), and class design rules. Apply whenever the project is a .NET 6+ project. Stack-agnostic — referenced by every .NET plugin in the marketplace. Use this skill to: -...

xUnit, Moq/NSubstitute, FluentAssertions, and coverlet patterns for any .NET project. Covers test structure ([Fact]/[Theory]/[InlineData]), mocking discipline, fluent assertions, integration test setup with WebApplicationFactory, and coverage measurement. Stack-agnostic — referenced by every .NET plugin in the marketplace. Use this skill to: - Write clear, maintainable unit tests with xUnit [Fact] and [Theory]. - Mock dependencies with Moq or NSubstitute without overusing mocks. - Write expr...

.NET SDK and NuGet tooling conventions: dotnet CLI commands (new/build/run/test/publish/restore/format), NuGet package management (PackageReference, Directory.Packages.props central package management, packages.lock.json), project file conventions (.csproj, .sln, global.json, Directory.Build.props), multi-targeting, and dotnet format. Stack-agnostic — referenced by every .NET plugin in the marketplace. Use this skill to: - Detect the .NET SDK version and run all commands via the dotnet CLI. ...

Django web framework conventions: app layout, settings split (base/local/production), URLconf with app namespacing, CBV and DRF ViewSets, DRF serializers and permissions, form validation, signals, Django admin registration, and middleware. Activated automatically by django-plugin/stack.md. Works alongside python-foundation:python-conventions and django-plugin:django-orm-patterns. Use this skill to: - Structure a Django project with multiple apps and correct URLconf hierarchy. - Write CBVs an...

Django ORM patterns: model definitions, field types, model managers, custom QuerySet methods, select_related/prefetch_related for N+1 prevention, transactions, F/Q expressions, Meta indexes and constraints. For django-architect (model definitions) and django-migrations-specialist (field finalization). Activated automatically by django-plugin/stack.md. Use this skill to: - Write clean, efficient Django model definitions with proper field choices and __str__. - Use custom managers and QuerySet...

FastAPI web framework conventions: APIRouter with prefix/tags/dependencies, Pydantic v2 schemas (BaseModel, model_config, field_validator, model_validator), dependency injection with Depends, async SQLAlchemy session yielding, OAuth2PasswordBearer + JWT auth, lifespan context manager, pydantic-settings configuration, OpenAPI customization, and HTTPException error handling. Activated automatically by fastapi-plugin/stack.md. Use this skill to: - Structure FastAPI apps with per-feature APIRout...

FastAPI-specific delta on top of python-foundation:sqlalchemy-patterns: async engine and AsyncSession lifecycle, get_db dependency injection, async-safe lazy loading rules, async Alembic env.py wiring. Used by fastapi-architect (model definitions) and alembic-specialist (column type finalization and migration generation). Activated automatically by fastapi-plugin/stack.md. Use this skill to: - Manage async database sessions with AsyncSession and async_sessionmaker. - Inject sessions into rou...

Flask web framework conventions: app factory pattern with create_app(), Blueprint registration with url_prefix, MethodView for class-based API views, Marshmallow schema validation, WTForms for HTML forms, Flask-Login for session auth, flask-jwt-extended for stateless API auth, Jinja2 template conventions, error handlers, and extension initialization. Activated automatically by flask-plugin/stack.md. Use this skill to: - Structure Flask applications with the app factory and per-feature Bluepr...

Flask-specific delta on top of python-foundation:sqlalchemy-patterns: Flask-SQLAlchemy extension setup, db.Model declarative models (3.x Mapped style and 2.x legacy db.Column), synchronous db.session lifecycle bound to the app context, Flask-Migrate integration. Used by flask-architect (model definitions) and flask-migrate-specialist (column finalization and migration). Activated automatically by flask-plugin/stack.md. Use this skill to: - Set up the SQLAlchemy and Migrate extensions with th...

Maven and Gradle build tool conventions for Java projects: build tool detection, wrapper usage, dependency management, BOMs, plugin configuration, semver, and multi-module layouts. Stack-agnostic — referenced by every Java plugin in the marketplace. Use this skill to: - Detect which build tool is in use and invoke it correctly. - Manage dependencies safely (BOMs, version properties, no wildcard versions). - Configure compiler, test, and code-quality plugins. - Handle multi-module projects. ...

Modern Java idioms for any JVM project (Java 17+): records, sealed types, text blocks, pattern matching, Optional discipline, streams, immutability, null safety, package layout, var usage, and code organisation. Apply when the project is a Java 17+ project. Stack-agnostic — referenced by every Java plugin in the marketplace. Use this skill to: - Write self-documenting, immutable-by-default value types with records. - Model closed type hierarchies with sealed classes and interfaces. - Handle ...

JUnit 5, Mockito, AssertJ, and Testcontainers patterns for any JVM project. Covers test structure, parameterised tests, mocking discipline, fluent assertions, and integration testing with real containers. Stack-agnostic — referenced by every Java plugin in the marketplace. Use this skill to: - Write clear, maintainable unit tests with JUnit 5. - Mock dependencies with Mockito without overusing mocks. - Write expressive assertions with AssertJ. - Spin up real infrastructure (DBs, message brok...

Package management discipline for any JavaScript/TypeScript project: dependency declaration, semver, scripts conventions, lockfile hygiene, package-manager detection (npm/yarn/pnpm). Stack-agnostic — referenced by every JS/TS framework plugin in the marketplace. Use this skill to: - Add a dependency correctly (right field, right semver range). - Pick the project's package manager from lockfile. - Define `scripts` entries that match conventions. - Avoid lockfile mistakes (manual edits, wrong ...

TypeScript discipline for any JavaScript/TypeScript project (frontend + backend): strict mode, type design, generics, narrowing, error types, module resolution, tsconfig hygiene. Apply when the project has `tsconfig.json` and `typescript` in devDependencies. Stack-agnostic — referenced by every JS/TS framework plugin in the marketplace. Use this skill to: - Write types that catch bugs at compile time, not runtime. - Use generics, conditional types, and discriminated unions correctly. - Avoid...

Eloquent ORM best practices: query builders, scopes, relations, N+1 prevention, batch operations, soft deletes, model events, raw queries when needed. Apply when: writing or reviewing Eloquent queries and model interactions. Activated automatically by laravel-plugin/stack.md as a convention skill for the development phase.

Consolidated Laravel project conventions: Action pattern, Form Requests, Policies, routing, Inertia integration, code style. Apply when: writing or reviewing Laravel backend code (controllers, actions, requests, policies, providers). Activated automatically by laravel-plugin/stack.md as a convention skill for the development phase.

NestJS decorator usage: built-in route/param/class decorators, custom decorators via `createParamDecorator` and `SetMetadata`, metadata reflection via `Reflector`. Apply when designing controllers, guards, interceptors, or custom decorators. Use this skill to: - Pick the right built-in decorator for routes, params, and DI. - Compose decorators (`@UseGuards(A, B) @UseInterceptors(C)`). - Build custom param decorators (e.g., `@CurrentUser()`). - Use metadata for role-based logic (Reflector + S...

GraphQL, WebSockets, and microservices patterns for NestJS. Apply only when the relevant package is in dependencies (`@nestjs/graphql`, `@nestjs/websockets`, `@nestjs/microservices`). Each section is orientation, not exhaustive — defer to NestJS docs for deep dives. Use this skill to: - Wire a GraphQL resolver (code-first) with class-validator inputs. - Build a WebSocket gateway with auth and room management. - Set up a microservice transport (TCP/RabbitMQ/NATS/Redis/Kafka) and message handl...

NestJS module structure, dependency injection, lifecycle, configuration, exception handling, and logging conventions. Apply when implementing or modifying NestJS backend code. Use this skill to: - Structure feature modules (one feature = one module). - Wire DI correctly (constructor injection, scopes, custom tokens). - Set up ConfigModule, ValidationPipe, exception filters in main.ts. - Use lifecycle hooks for init and graceful shutdown. - Pick the right exception class for each error case. ...

ORM patterns for NestJS: TypeORM, Prisma, Mongoose. Covers entities, repositories, transactions, migrations, common pitfalls (N+1, cascade deletes, transaction boundaries). Use this skill to: - Detect which ORM the project uses and apply matching patterns. - Define entities/schemas with the right decorators. - Inject repositories or Prisma client correctly. - Run transactions at the service boundary. - Write migrations that round-trip cleanly. Do NOT use this skill for: - Module/DI patterns...

NestJS testing patterns: Test.createTestingModule for unit/integration, mocking providers, e2e tests with INestApplication + supertest, ORM mocking (TypeORM/Prisma/Mongoose), test fixtures. Use this skill to: - Write unit tests for services with mocked dependencies. - Write integration tests with real DI but mocked external services. - Write e2e tests for HTTP endpoints via supertest. - Mock repositories/Prisma client correctly. - Cover services and controllers to ≥80%. Do NOT use this skil...

Next.js project structure, App Router conventions, file-based routing primitives, layouts, error boundaries, metadata, image and font optimization, configuration. Apply when implementing or modifying Next.js features. Use this skill to: - Pick the correct file convention (page/layout/loading/error/not-found/route/template/default). - Structure a feature within the App Router tree. - Set up metadata for SEO and OpenGraph. - Configure next.config.js for headers, redirects, image domains. - Use...

Data fetching, caching, and revalidation patterns in Next.js App Router. Covers native fetch caching, ISR/SSG/SSR per-route choice, generateStaticParams, unstable_cache, revalidatePath/revalidateTag, Route Handlers, dynamic vs static rendering. Use this skill to: - Pick the right rendering mode (SSG / ISR / SSR / streaming) per route. - Use native fetch caching options correctly. - Build Route Handlers that match REST conventions. - Invalidate cached data after mutations. - Use generateStati...

Next.js App Router routing primitives: file-based routes, dynamic and catch-all segments, route groups, parallel routes, intercepting routes, middleware, programmatic navigation, link patterns. Use this skill to: - Pick the correct dynamic segment syntax for the route shape. - Use route groups to organize without affecting URLs. - Implement parallel/intercepting routes for modal-style navigation. - Build effective middleware for auth, redirects, A/B tests. - Use Link and useRouter correctly....

Testing strategies for Next.js: Server Components, Client Components, Server Actions, Route Handlers, end-to-end with Playwright. Vitest/Jest configuration, React Testing Library patterns, msw for network mocks. Use this skill to: - Pick the right test layer for what you're testing. - Configure Vitest or Jest for Next.js. - Test Server Components without running them in isolation. - Test Server Actions and Route Handlers as pure functions. - Set up Playwright for e2e and integration of RSC. ...

React Server Components vs Client Components in Next.js: the boundary discipline, "use client" / "use server" directives, Server Actions, what serializes across the boundary, common pitfalls. Use this skill to: - Decide whether a component should be RSC or Client. - Push the "use client" boundary as deep as possible. - Implement Server Actions correctly (auth, validation, revalidation). - Compose RSC and Client components without breaking the model. - Pass data across the boundary safely. D...

Node.js backend conventions: project layout, configuration, logging, routing, and error handling patterns. Apply when implementing or modifying Node.js backend code in projects matching the nodejs stack profile. Use this skill to: - Pick conventional file/folder structure for a new module. - Wire configuration through env vars correctly. - Use the project's existing logger style. - Implement error handling that matches the framework (Express/Fastify/Koa). - Follow async/await patterns consis...

Composer conventions for any PHP project: dependency management, version constraints, PSR-4 autoloading, scripts, platform requirements, and the composer.json vs composer.lock contract. Stack-agnostic — referenced by every PHP plugin in the marketplace. Use this skill to: - Read composer.json to detect the PHP version, framework, and key packages before writing code. - Add dependencies with correct version constraints and the right require vs require-dev placement. - Configure PSR-4 autoload...

Modern PHP idioms for any PHP project (PHP 8.1+): readonly properties, enums, match expressions, constructor property promotion, typed properties, named arguments, nullsafe operator, first-class callable syntax, strict_types, PSR-12 style, and null discipline. Apply when the project is a PHP 8.1+ project. Stack-agnostic — referenced by every PHP plugin in the marketplace. Use this skill to: - Write strongly-typed, immutable-by-default value objects with readonly properties and enums. - Repla...

PHPUnit and Pest patterns for any PHP project: test structure, naming, data providers, test doubles (mocks/stubs/fakes), fixtures, and coverage targets. Stack-agnostic — referenced by every PHP plugin in the marketplace. Use this skill to: - Structure unit and integration tests with PHPUnit or Pest consistently. - Drive cases with data providers / datasets instead of copy-pasted test bodies. - Use test doubles with discipline — mock collaborators, not the system under test. - Set up and tear...

pytest testing patterns for any Python project: test structure, fixtures, parametrize, conftest.py, monkeypatch, tmp_path, markers, unittest.mock (MagicMock, patch), pytest-cov coverage, and best practices. Stack-agnostic — referenced by every Python plugin in the marketplace. Use this skill to: - Organise tests with conftest.py shared fixtures and a clear test/src layout. - Write parametrized tests to cover multiple inputs without duplication. - Mock external dependencies (HTTP, DB, filesys...

Modern Python idioms for any Python 3.10+ project: PEP 8 style, PEP 484/526 type hints, dataclasses, pathlib, enums, f-strings, structural pattern matching (match/case), context managers, exception handling, and null discipline. Stack-agnostic — referenced by every Python plugin in the marketplace. Use this skill to: - Write strongly-typed code with type hints on every function signature and class attribute. - Replace isinstance chains and magic constants with match/case and enums. - Use dat...

Python project tooling: pyproject.toml as the single source of truth, package managers (pip, Poetry, uv, pipenv), virtual environments, lockfiles, ruff (lint + format), mypy (type checking), and console scripts / entry points. Stack-agnostic — referenced by every Python plugin in the marketplace. Use this skill to: - Read pyproject.toml (or requirements.txt / Pipfile) to learn which package manager and Python version the project uses. - Install, add, and remove dependencies with the project'...

Framework-agnostic SQLAlchemy 2.0 core shared by fastapi-plugin and flask-plugin: declarative mapped classes with Mapped/mapped_column, column type selection, relationships with explicit lazy loading and cascades, 2.0-style select() querying, transaction/flush discipline, and Alembic-agnostic migration metadata rules. Framework plugins layer their delta skills (async sessions for FastAPI, Flask-SQLAlchemy integration for Flask) on top of this skill. Use this skill to: - Write SQLAlchemy 2.0 ...

Application and library conventions for plain Python projects (no web framework): src/ package layout, CLI tooling (argparse/click/typer), configuration management (pydantic-settings), logging setup, module design, entry points, and packaging conventions. Activated automatically by python-plugin/stack.md as a convention skill for the development phase. Use this skill to: - Organise Python application code in a src/ layout with proper package structure. - Build CLI tools with argparse, click,...

React Native project structure, Expo vs bare workflow detection, app.json/app.config.js patterns, asset handling, fonts, styling approaches, hot-reload-friendly idioms. Use this skill to: - Detect Expo (managed/dev-client/EAS/ejected) vs bare RN workflow. - Pick correct project layout for each workflow. - Configure app.json / app.config.js with bundle ID, splash, icons, deep link schemes. - Handle assets, fonts, images correctly. - Pick a styling approach (StyleSheet / NativeWind / restyle /...

Navigation in React Native — both React Navigation v7 (classical, modular) and Expo Router (file-based, Expo 49+). Stack, tab, drawer navigators, deep linking, typed navigation, modal presentation, authentication flow patterns. Use this skill to: - Pick navigation lib based on what's installed (@react-navigation/* vs expo-router). - Configure typed routes with ParamList types or Expo Router's generated types. - Set up deep linking (URL schemes, Universal Links, App Links). - Build authentica...

iOS / Android platform-specific code in React Native: Platform.OS, Platform.select, .ios.tsx / .android.tsx file extensions, native modules, permissions, safe area handling, status bar. Use this skill to: - Branch code at runtime via Platform.OS / Platform.select. - Use file extensions for whole-component swaps. - Link and use native modules (Expo SDK or autolinked bare). - Handle permissions across platforms. - Configure status bar and safe area correctly. Do NOT use this skill for: - Gene...

State management and storage choice in React Native. State libs work mostly the same as web (Zustand, Jotai, Redux Toolkit, TanStack Query, Context); storage choice is RN-specific — AsyncStorage, MMKV, SecureStore, Keychain. Hydration patterns, splash screen handling, secrets discipline. Use this skill to: - Pick state management lib (matches web React intuition). - Pick storage by sensitivity (AsyncStorage / MMKV / SecureStore / Keychain). - Hydrate state on app start without UI flicker. - ...

Testing React Native: Jest with jest-expo / react-native preset, React Testing Library Native, native module mocking, hook testing. Optional sections for Detox (native automation) and Maestro (declarative YAML e2e). Use this skill to: - Configure Jest preset based on workflow. - Write component tests with @testing-library/react-native. - Mock native modules (react-native-reanimated, expo-*, react-native-mmkv). - Test custom hooks via renderHook. - Set up Detox or Maestro for e2e (optional, r...

React component structure, hooks rules, file naming, project layout, composition patterns, performance idioms, and effects discipline. Apply when implementing or modifying React SPA code. Use this skill to: - Structure a new component or feature folder. - Apply hooks correctly (rules, naming, dependency arrays). - Compose components via children, render props, or compound patterns. - Write effects only when needed (and avoid common misuses). - Pick performance escape hatches (memo, useMemo, ...

Form patterns for React: react-hook-form (most common), Formik (legacy/stable), TanStack Form (newer). Validation via zod / yup / valibot. Controlled vs uncontrolled inputs, field arrays, multi-step wizards. Use this skill to: - Wire react-hook-form with a validation schema. - Pick between controlled and uncontrolled patterns. - Build multi-step forms with state preservation. - Handle async validation (e.g., username availability). - Integrate forms with TanStack Query mutations. Do NOT use...

Routing libraries for React SPAs: React Router v6/v7 (most common), TanStack Router (typed, modern), wouter (minimal). Detect what's installed and apply matching patterns. Lazy loading, navigation guards, typed params. Use this skill to: - Configure routes (declarative or file-based). - Use navigation hooks (useNavigate, useParams, useSearchParams). - Lazy-load routes for code splitting. - Implement protected routes / auth guards. - Type-safe params via Zod or framework's built-ins. Do NOT ...